Fluid dynamic control device

摘要

1,130,031. Pure fluid switches. MATTEL Inc. Oct.1, 1965 [Feb. 4, 1965], No.43020/65. Heading G3H. [Also in Division H1] A pure fluid dynamic control device comprises a blower 18, Fig. 1 supplying fluid to an accumulator chamber 22 having an outlet slot 28 through which a stream exists as a laminar flow. A first boundary wall 42, 44 is spaced from the slot by a spacer 40 while a second boundary wall 52, 56 is arranged opposite but downstream of the first wall. A throat 66 between the second wall and slot leads to a resonant chamber 60 which may be adjustable in size by a slide 62. Under normal conditions, the issuing jet locks on to the wall 42, 44 but in the event of a sound at a frequency which sets the chamber 60 in resonance, vortices are formed at the throat 66 and a pressure difference created which pulls the jet over to the second wall 52, 56 until the sound ceases when the jet switches back to the first wall. In a modification, two resonators are employed located on opposite sides of the jet outlet to switch the jet at different frequencies. The blower may be arranged in the body as in Fig.7 (not shown) and the jet is used to actuate a pivoted vane 90 loaded by a spring to make or brake switch contacts 92, 96 as the jet is switched. The device may also be used as a jet propulsion device, Figs.14 and 15 (not shown) in which the jet provides a thrust in one direction under normal circumstances but in a second direction when the jet is switched. The blower may also supply two jets which may be switched at different frequencies. In a further modification, the device is used with an air cushion vehicle in which the jet or jets are manually directed to the peripheral nozzles around the circumference of the vehicle but in response to sound at certain frequencies, the jet is deflected to apply a thrust component to the vehicle.